Updated

Greg Biffle says he plans to apologize to Jimmie Johnson for how he handled his displeasure with the five-time champion at Martinsville.

Biffle angrily grabbed Johnson by the collar and spun him around while Johnson was being interviewed on pit road after Sunday's race. Biffle believed Johnson had run into the back of his car, causing the bumper to fall off and preventing Biffle from racing for the win.

Biffle said Tuesday he's going to call Johnson to apologize. He says he wishes he'd had a private conversation with Johnson, and should have grabbed his arm to get his attention.

But he remains convinced that contact from Johnson ripped off the bumper, and fans who claimed the damage was done by Dale Earnhardt Jr. are wrong.